Mode of work of gas-steam power unit with the closed contour of circulation of gas

ABSTRACT

This invention relates to gas-steam power plants with the closed contour of circulation of gas and can be used at nuclear power plants. They heat up gas in a heater ( 1 ), then direct heated gas into gas turbine ( 2 ) where transform a part of heat of this gas into mechanical work, then transfer part of heat of this gas to liquid in steam heater ( 3 ), vaporizer ( 4 ) and heater of a liquid ( 5 ) connected in series on a way of a liquid and direct the steam received on an outlet of steam heater ( 3 ) into steam turbine ( 12 ). They compress the cooled in heat exchangers ( 3 ), ( 4 ) and ( 5 ) gas by multistage compressor ( 6 ) and return gas into heater ( 1 ) for repeated heating. In additional heat exchangers ( 7 ) in parallel with vaporizer ( 4 ) on a way of a liquid they additionally vaporize a liquid by heat of gas, heated at stages of the multistage compressor ( 6 ). After vaporizing of a liquid they additionally heat up received steam in the steam heater ( 3 ), installed by the first on a way of the gas after gas turbine ( 2 ). They direct steam after steam heater ( 3 ) into steam turbine ( 12 ) for transformation of steam energy into mechanical work. The division of process of vaporizing of a liquid by heat of gas into steps located in series on a way of the gas through stages of the compressor ( 6 ) at parallel submission of the vaporizing liquid to these steps allows to reduce the change of temperature difference between gas and a liquid in vaporizers ( 4 ) and ( 7 ) in the number of times corresponding to number of these steps, i.e. to raise temperature of vaporizing a liquid without changing parameters of gas turbines. Due to it the increase in thermal efficiency of gas-steam power unit with the closed contour of circulation of gas is reached.

FIELD OF THE INVENTION

This invention relates to gas-steam power plants with the closed contour of circulation of gas.

PRIOR ART

Mode of work of gas-steam power plant with the closed contour of circulation of gas is known, characterized in that they heat up gas in a heater, direct the heated gas into the gas turbine where transform a part of heat of this gas into mechanical work, then transfer the part of heat of this gas to liquid in heat exchangers connected in series on the way of a liquid that transfers into steam in these heat exchangers, after that they compress the cooled gas by the compressor and return gas into a heater for repeated heating, and direct the steam received from a liquid into steam turbines for transformation of steam energy into mechanical work (see a book by B. G. Ganchev, etc., under N. A. Dollezhal's general edition, “Nuclear Power Plants”, the Manual for High Schools, Moscow, Nuclear Power Publishing House, 1990, p. 124).

At this mode a liquid evaporates with big change of a temperature difference between gas and a liquid because the gas temperature decreases when gas is under cooling but the temperature of evaporating liquid is constant. The big change of a temperature difference between gas and a liquid in the evaporator limits thermal efficiency of closed gas-steam cycle because of restriction of temperature of evaporating of a liquid at the preset parameters of the gas turbine.

SUMMARY OF THE INVENTION

The present invention is directed on decision of task of increasing the efficiency of transfer of thermal energy from heated gas into a liquid.

Technical result of the invention is the increase of thermal efficiency of gas-steam power plants with the closed contour of circulation of gas.

The specified problem will be solved, and the technical result will be reached by the mode of work of gas-steam power unit with the closed contour of circulation of the gas, mode in that they heat up gas in a heater and direct the heated gas into the gas turbine where transform a part of heat of this gas into mechanical work, then transfer the part of heat of this gas to liquid in heat exchangers connected in series on a way of a liquid that transfers into steam in these heat exchangers, after that they compress by the compressor the gas that was cooled in heat exchangers, they return gas into a heater for repeated heating and direct the steam received from a liquid into steam turbines for transformation of steam energy into mechanical work, moreover they compress gas in the multistage compressor, install between stages of the compressor additional heat exchangers vaporizing a liquid by heat of this gas, and after evaporating of a liquid they heat up received steam in the steam heat exchanger installed by the first on a way of the gas after gas turbine, moreover in the second heat exchanger on a way of the gas after gas turbine they vaporize a liquid, in the third heat exchanger on a way of the gas after gas turbine they warm up a liquid up to the temperature close to temperature of boiling, withal simultaneously vaporize a liquid in the additional heat exchangers connected in parallel on a way of a liquid with heat exchanger vaporizing a liquid and in series among themselves on a way of the gas through stages of the compressor.

By a choice of a degree of compression of gas at stages of the compressor and by regulation of the flow of a liquid through heat exchangers they provide, preferably, identical temperature of gas in outlets of heat exchangers vaporizing a liquid.

They can heat up gas in a heater, at least, in two stages, and after an outlet from the first stage they direct the heated gas into connected in parallel among themselves after the first stage of the heater additional gas turbines for transformation into mechanical work the part of heat of gas heated in the first stage.

They can heat up steam in steam heat exchanger in series in two sections, moreover transform a part of heat of steam into mechanical work in additional steam turbines installed on a way of this steam between these sections and direct gas into these sections by parallel streams.

With considering that a liquid evaporates with big change of a temperature difference between gas and a liquid because the gas temperature decreases when gas is under cooling, but the temperature of evaporating liquid is constant, division of process of vaporizing of a liquid by heat of gas into steps located in series on a way of the gas through stages of the compressor at parallel submission of an vaporizing liquid to these steps allows to reduce change of said temperature difference in heat exchangers vaporizing a liquid in the number of times corresponding to number of these steps, i.e. to raise temperature of vaporizing a liquid without changing parameters of gas turbines. Due to it the increase in thermal efficiency of gas-steam power unit is reached.

By a choice of a degree of compression of gas at stages of the compressor and by regulation of the flow of a liquid through heat exchangers they provide identical temperature of gas in outlets of heat exchangers vaporizing a liquid. Due to it is possible to support the minimal temperature difference between gas and a liquid in these heat exchangers and accordingly to support the maximal temperature of vaporizing of a liquid.

They can heat up gas in a heater, at least, in two stages, between which transform the part of heat of this gas into mechanical work in additional gas turbines. It will allow to increase a degree of compression of gas and accordingly to increase thermal efficiency of gas-steam power unit without changing maximal temperature of gas.

They can heat up steam in steam heat exchanger in series in two sections, moreover transform a part of heat of steam into mechanical work in additional steam turbines installed on a way of this steam between these sections and direct gas into these sections by parallel streams. Giving of gas in parallel into sections of steam heat exchanger facilitates regulation of working regime of the steam turbine.

BRIEF DESCRIPTION OF THE DRAWINGS

On the drawing the basic scheme of gas-steam power unit with the closed contour of circulation of gas is presented.

Gas-steam power unit with the closed contour of circulation of gas contains a heater (1), connected to it gas turbine (2), connected in series on a way of a liquid the heat exchangers (3), (4) and (5), and the multistage compressor (6). The heat exchanger (4) is vaporizer and the heat exchanger (3) is steam heater. Between stages of the compressor (6) the additional heat exchangers (7) are installed. They are connected in parallel on a way of a liquid with vaporizer (4) and in series among themselves on a way of the gas through stages of the compressor (6).

The heater (1) is executed two-stage, and after first stage (8) of heater (1) the additional gas turbines (9) are installed in parallel. Gas turbine (2) is connected to an outlet of the second stage (10) of heater (1).

The steam heater (3) consists of two sections (11) and (13), between them on a way of the steam is installed additional steam turbine (14). Second section (11) on a way of the steam is connected to the steam turbine (12).

DESCRIPTION OF THE PREFERRED EMBODIMENT

Mode of work of gas-steam power unit with the closed contour of circulation of gas is as follows. They heat up gas in a heater (1), then direct heated gas into the gas turbine (2) where transform a part of heat of this gas into mechanical work, then transfer part of heat of this gas to liquid in heat exchangers (3), (4) and (5) connected in series on a way of a liquid and direct the steam received on an outlet of heat exchanger (3) into the steam turbine (12). They compress the cooled in heat exchangers (3), (4) and (5) gas by multistage compressor (6) and return gas into heater (1) for repeated heating. In additional heat exchangers (7) in parallel with vaporizer (4) on a way of a liquid they additionally vaporize a liquid by heat of gas, heated at stages of the multistage compressor (6). After vaporizing of a liquid they additionally heat up received steam in the steam heater (3), installed by the first on a way of the gas after gas turbine (2). They direct steam after steam heater (3) into the steam turbine (12) for transformation of steam energy into mechanical work of rotation of a shaft of the steam turbine (12). In the second heat exchanger (4) on a way of the gas after gas turbine (2), as said above, they vaporize a liquid and in the third heat exchanger (5) on a way of the gas after gas turbine (2) they warm up a liquid up to the temperature close to temperature of boiling.

By a choice of a degree of compression of gas at stages of the compressor (6) and by regulation of the flow of a liquid through vaporizers (4) and (7) they provide, preferably, identical temperature of gas at an outlet from vaporizers (4) and (7).

They can heat up gas in a heater (1), at least, in two stages (9) and (10), and after an outlet from the first stage (8) they direct the heated gas into connected in parallel among themselves after the first stage (8) of the heater (1) additional gas turbines (9) for transformation into mechanical work the part of heat of gas heated in the first stage (8).

They can heat up steam in steam heat exchanger (3), as said above, in series in two sections (11) and (13), moreover transform a part of heat of steam into mechanical work in additional steam turbines (14) installed on a way of this steam between these sections (11) and (13) and direct gas into these sections by parallel streams.

INDUSTRIAL APPLICABILITY

This invention can be used at power plants, for example at nuclear power plants. 

1. Mode of work of gas-steam power unit with the closed contour of circulation of the gas, mode in that they heat up gas in a heater and direct the heated gas into the gas turbine where transform a part of heat of this gas into mechanical work, then transfer the part of heat of this gas to liquid in heat exchangers connected in series on a way of a liquid that transfers into steam in these heat exchangers, after that they compress by the compressor the gas that was cooled in heat exchangers, they return gas into a heater for repeated heating and direct the steam received from a liquid into steam turbines for transformation of steam energy into mechanical work, CHARACTERIZED IN THAT they compress gas in the multistage compressor, install between stages of the compressor additional heat exchangers vaporizing a liquid by heat of this gas, and after evaporating of a liquid they heat up received steam in the steam heat exchanger installed by the first on a way of the gas after gas turbine, moreover in the second heat exchanger on a way of the gas after gas turbine they vaporize a liquid, in the third heat exchanger on a way of the gas after gas turbine they warm up a liquid up to the temperature close to temperature of boiling, withal simultaneously vaporize a liquid in the additional heat exchangers connected in parallel on a way of a liquid with heat exchanger vaporizing a liquid and in series among themselves on a way of the gas through stages of the compressor.
 2. Mode according to claim 1, CHARACTERIZED IN THAT by a choice of a degree of compression of gas at stages of the compressor and by regulation of the flow of a liquid through heat exchangers they provide identical temperature of gas in outlets of heat exchangers vaporizing a liquid.
 3. Mode according to claim 1, CHARACTERIZED IN THAT they heat up gas in a heater, at least, in two stages, and after an outlet from the first stage they direct the heated gas into connected in parallel among themselves after the first stage of the heater additional gas turbines for transformation into mechanical work the part of heat of gas heated in the first stage.
 4. Mode according to claim 1, CHARACTERIZED IN THAT they heat up steam in steam heat exchanger in series in two sections, moreover transform a part of heat of steam into mechanical work in additional steam turbines installed on a way of this steam between these sections and direct gas into these sections by parallel streams. 